Pentax has been a leader in the photographic field for many years. Many Pentax innovations have become standards in the industry. Pentax's enthusiasm and devotion towards the development of high-quality products have thrived over the years and continues to be stronger than ever. PRODUCT FEATURES: Utilizing Pentax XL telescope eyepieces, renowned for sharpness, field of view, contrast, and freedom from aberration; Extra Low Dispersion (ED) optics for optimum optical resolution; Large 80mm objective lenses for bright viewing under all light conditions; 20mm eye relief; Accepts all standard 1 1/4 inch interchangeable telescope eyepieces; Waterproof nitrogen filled; Famous Pentax Super-Multi-Coating maximizes light transmission, clarity, and contrast; Lightweight magnesium alloy housing; Extended eyecup allows for variable adjustment to accommodate eye relief for individual user; Built-in lens shade; Magnification: 20x - 60x; Lens Structure: 6 elements 4 groups; Real Field of View: 1.9-1; Apparent Field of View: 38-60; Field of View at 1000 m: 33 - 17m; Field of View at 1000 yd: 108- 56ft; Exit Pupil: 4 - 1.3mm; Eye Relief: 20mm; Relative Brightness: 16 - 1.7; Eyepiece Size Lens & Outside Diameter: 5.7 x 2.7in. (144 x 69mm); Weight (Eyepiece): 19.2 oz. (550g).